Clustered Defects in IC Fabrication: Impact on Process Control Charts

David J. Friedman, Susan L. Albin

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


A control chart is a graphical record of sample measurements to track a manufacturing process over time. Measurements above or below control limits alert operators and engineers that the process is out-of-control. In IC fabrication, standard process control charts for defects often sound many false alarms, i.e., the chart incorrectly indicates the process is out-of-control. The cause for these false alarms in some cases: defects in IC fabrication tend to cluster, basic assumptions that support the construction of standard control charts for defect data. A method for distinguishing between data from an in-control process that yields clustered defects and data from an out-of-control process is contained. Further, a method for constructing defect control charts for processes that yield clustered defects is presented.

Original languageEnglish (US)
Pages (from-to)36-42
Number of pages7
JournalIEEE Transactions on Semiconductor Manufacturing
Issue number1
StatePublished - Feb 1991

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


Dive into the research topics of 'Clustered Defects in IC Fabrication: Impact on Process Control Charts'. Together they form a unique fingerprint.

Cite this